Morar will buy the remaining 15% of the business in June 2018, with the value based on HPI’s operating profit for the financial year ending 31 January 2018.

HPI’s revenues were £3.41m for the year ended 30 September 2016 and its clients include Sainsbury’s, Argos and Heineken.

Juliet Strachan will remain managing partner of the 50-strong agency which first opened its doors in 1978 as Hudson, Payne and Iddiols.

HPI also incorporates EnvirosellUK, its shopper capabilities and environmental research and consulting division, and works alongside Cardinal, the licensed trade and drinks market company – Martin Dinkele will continue to head Cardinal. All three brands will become a part of Next 15.

David Iddiols will be leaving the business at the end of the year although he will continue to consult on some projects and accounts.

Strachan said: "Bringing HPI together with Next 15 agencies such as Morar is a perfect match; with access to advanced systems and technology and HPI’s insight and consultancy, we will be able to deliver industry leading research solutions for all our clients.

"It will allow us to deliver new ideas, thinking and approaches into 2017. In the short term it’s business as usual for our clients and team, but better, faster and with genuine new thinking."

Tim Dyson, CEO of Next 15, said: "This acquisition is in line with Next 15’s strategy of growing its data revenue to 20% of group revenue in the next five years.

"HPI brings both talent and a history of high quality market research. We believe that a combination of HPI’s team and established client base with Morar’s technology platform will create a better solution for HPI’s customers and enable Morar to reach new customer segments."